1. Field of the Invention
The present invention relates to a musical piece correction program and a musical piece correction apparatus. The present invention particularly relates to a musical piece correction program and a musical piece correction apparatus for correcting sounding timings of sounds constituting a musical piece.
2. Description of the Background Art
Conventionally, in the technical field of information processing for music performance data of a musical piece, there is processing called quantization for automatically correcting a sounding timing indicated by the music performance data. The quantization processing is for automatically adjusting the sounding timing indicated by the music performance data such that the sounding timing coincides with an ideal timing (quantized timing, typically a timing of sounding a note).
The above quantization processing has a problem in that a plurality of sounds having different sounding timings in the music performance data are corrected by the quantization processing such that the plurality of sounds have a same sounding timing. In order to solve this problem, an automatic music performance data correction apparatus disclosed in Patent Document 1 (Japanese Lain-Open Patent Publication No. 6-250648) shifts a sounding timing or deletes a sound from among a plurality of sounds whose sounding timings have been corrected to be at a single timing. To be specific, after the quantization processing, the automatic music performance data correction apparatus detects whether there are a plurality of sounds whose sounding timings have been corrected to be at a single timing, and, if there are, deletes a sound whose gate time (length of the sound) is shorter, or shifts one of the sounds to an adjacent quantized timing.
However, there may be a case where a music performance indicated by the music performance data includes not only sounds which are intended to be produced at quantized timings but also sounds which are intended to be produced at different timings from quantized timings. For example, in the case where the music performance data is inputted by, e.g., a person, the person (i.e., a user) may input the music performance data such that sounds are produced at different timings from quantized timings (hereinafter, referred to as improvised inputting). However, the automatic music performance data correction apparatus disclosed in Patent Document 1 eventually shifts sounding timings of all the sounds to quantized timings. For this reason, there is a case where an intention of the user, which is originally contained in the music performance data, is lost due to the quantization processing. In other words, when a method for adjusting the sounding timings of all the sounds to quantized timings is used, the corrected music performance data does not reflect at all an intention of the user (to deliberately deviate sounding timings from quantized timings). Thus, in the conventional quantization processing, the processed music performance data is standardized, and the conventional quantization processing does not support the improvised inputting by the user.